Hell Below

The USS Harder, led by Commander Sam Dealey, sank multiple Japanese destroyers, rescued Allied operatives from capture in Borneo, and outmatched many rival ships and aircraft to return home. And that was during just one patrol. Take a deep dive aboard this submarine as we relive this incredible war patrol in the spring of 1944, and witness the events that accelerated the campaign against the Japanese and earned Dealey the Medal of Honor.

The wolfpack tactic was made famous by Admiral Karl Donitz, Hitler's mastermind of submariners. His strategy: to send teams of U-boats to bear against the convoys of ships heading from Canada to Britain, cut maritime lifelines, and starve the enemy into defeat. Take a deep dive into the North Atlantic as we go above and below sea level to relive one of the first attacks of Donitz's lethal subs in 1940, headed by leader of the pack Commander Otto Kretschmer. Then follow Britain's war strategists as they race to combat this new deadly attack.

Just one month after the Japanese attack on Pearl Harbor, another enemy brought World War II to American shores, not through the air but beneath the sea. This is the story of Operation Drumbeat, German Admiral Karl Donitz's campaign to send U-boats to the doorstep of the U.S. and attack Allied merchant shipping from Newfoundland to North Carolina. Through archival war footage and military expert testimony, we reveal how the Nazis managed to hammer our coast again and again and why the U.S. Navy was unable to stop them.

A Nazi U-boat heading back for repairs unintentionally cruises right into the middle of a large Allied convoy on March 16, 1943. It is a lucky accident that sets the stage for the largest convoy battle of World War II. Relive this momentous chapter in the war for the Atlantic, an intense game of chess pitting Admiral Karl Donitz's wolf pack against a battered British Navy. It's a three-day showdown with unparalleled violence and unexpected outcomes that will turn the tide of the war.